Bone mineral density as a prognostic factor for curve progression in adolescent idiopathic scoliosis: a longitudinal validation study

Methods A cohort of 60 patients with a mean age of 12.6 years old (SD=0.8) and an average Cobb angle of 21.4 (SD=6.3) degrees were followed from their first visit till skeletal maturity defined as Risser 4 or above and greater than 1.5 years postmenarchal. Progressive curves were defined as a cumulative increase of 6 degrees or more in the Cobb angle, or the magnitude of any curve exceeding 45 degrees or the patients receiving surgery recommendation before or at skeletal maturity. BMD was measured with Dual Energy X-ray Absorptiometry of bilateral femoral necks at the first visit. Other anthropometric measurements such as body weight, body height and Tanner staging were also recorded at baseline.